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New data. Cammed flat top 5.3 help!
I have a fresh build lm7 based engine. I have changed usual parameters for a cam swap but am having issues with idling still and have lack of idle control in my scanner when the engine is running too.
Engine is stock LM7 with exceptions of Summit 8706 stage 2 turbo cam, flat top pistons, and dual valve springs.
Cam Specs:
Summit Racing SUM-8706: Stage 2 Pro LS Turbo Cam. 226/230 Dur., 113+4, .600/.575 Lift, 3-bolt, 5.3, 5.7, 6.0, 6.2, 7.0, Vortec Truck, LS1 LS2 LS6 LS3 LS7 LQ4 LQ9 LS9, Each
This motor is in my crawler with a th400 and np205 behind it with 4.56 gearing. At this time, the motor will idle for a short amount of time and needs throttle to start. Only other issue I am having is slightly lower fuel pressure at 55psi, but that will be fixed soon.
At this point I have done a typical change to target idle tables and airflow tables. This motor will not start without throttle at all. I am not sure if the compression increase is also causing problems to typical changes for cam tuning. Just added the wideband hoping for more answers and it reads 14.7 when unplugged from the o2, but goes to around 11-12 when running. It also remains at around 11 when running and the plugs were pretty carbon coated. It does have times of running fairly good but then will die with any chence of trying to let it idle on its own. Wideband is installed correctly per the manual and is around 24 inches down stream with plenty of exhaust behind it. I also checked for vacuum leaks and came up with nothing.
I am not sure why this motor will not idle. Also runs rough when giving it gas but will smooth out at higher RPMS. Car will pop off for a quick second when no throttle is given but that is all.
If someone could even PM me their number or something I would really appreciate ito. I have been trying to get this thing going for quite some time now and can only scratch my head.
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Tried new tune-slightly altered
Hey guys, So I changed the tune a little but it seems changing the desired idle is still not doing anything. I did get the motor to sit and idle on its own but now it will not do it again. I am really scratching my head but will attach what I got for the time it idled on its own and some files from when it will not anymore. I thought I was onto something with it idling and I was able to rev it up. It would fall on its face during rev up slightly, but I thought it was progress. I guess not...
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New data logs. Where to go from here?
Quote:
Originally Posted by
R0G3R
Attachment 97668
try this file, i have updated the fuel tables at idle areas, timing areas at idle and adjusted startup airflow. get a log of how it idles at hot restart.
Ok, I used this file and still needed throttle to get it started, but besides that it seemed to run fairly well. Slight stutter when revving up and it would die if I let the RPM's drop without feathering the throttle back down. Got up to temp and still no hot start without some pedal. Where to I go from here. Thank you by the way! Also I am running about 56-57 psi fuel at idle.
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